Automatic drive problems

[alantemperton]

My CLK430 2001 AMG (105,000 miles, regularly serviced) has suddenly devloped drive problems. It all started with slight hesitation when starting from stationary .... and when slowing down for a junction or roundabout and then accelerating away the car surged forward as though someone hit you up the rear. On first starting in the morning it then refuses to change from 2nd gear. Stop, switch off and take the key out and all is fine. Yesterday, for the first time it would not change into top gear. Again, stop, switch off and all is fine.

My mercedes specialist diagnoses the problem as requring a new torque converter but also includes in the 'worst case' quote a valve body. Says that it is a waste of money to replace the ATF as the problem has gone beyond that (the car has never had a fluid or filter change).

My concern is .... if it was torgue converter, why is it sometimes just fine. The quote seems as though they are still not sure ..... sort of ... lets fit a torque converter and if that does not sort the problem then it must be the valve body. Why would someone include a valve body in the quote if they believed it to be the torque converter.

Why do the computer faults not show up the real fault?

The estimate for this repair is over £2K - how do I get a realiable second opinion? Any help/suggestions greatly appreciated.

 

[Dieselman]

It could be either or both of the faults mentioned.
MAF sensor can also cause hard shifts and other problems but it does sound as this may be more than that.

On balance it does sound like the torque converter although I'm not sure about the failure to change up. What fault codes have been pulled from the gearbox ECU?

 

[alantemperton]

When they looked at the car they mentioned that there were a few faults on the 'computer'. On the back of that they replaced two plug leads because of 'misfire'. This has made no difference whatsoever to my reported drive problems. They have not mentioned any fault codes in the gearbox ecu.

I am really unsure what to do next - take it to another mercedes or auto trans specialist for a second opinion albeit I have spoken with them on the phone and both have said that it doesn't sound like TC to them.

Others in the forum have reported similar faults to mine but no answer has ever suggested torque converter !!!

 

[BTB 500]

Whereabouts are you? Someone may be able to suggest a good place to go for a 2nd opinion.

 

[alantemperton]

I am based in Bicester ... so anywhere in Oxfordshire, Bucks or Northants.

 

[Parrot of Doom]

I know on some mercedes models there is a design flaw in the radiator, coolant leaks into the transmission fluid - but I'm not certain which models it applies to. IIRC its called the Valeo problem?

There is a glycol test, usually replacing the torque convertor is the fix. I believe Mercedes have been replacing these as a good will gesture.

I'm just repeating parrot-style what I've heard, it may not even affect your model.

 

[BlackC55]

The 208 is not affected by the glycol problem.

 

[Parrot of Doom]

Ah right

 

[television]

Dont forget with gearbox ECU's you have to have the fault codes read out before you switch off the engine and the fault is present.

 

[BTB 500]

Dont forget with gearbox ECU's you have to have the fault codes read out before you switch off the engine and the fault is present.

Not on my '97 SL ... the fault codes relating to occasional limp home mode were all there when they hooked up the reader.

 

[television]

Not on my '97 SL ... the fault codes relating to occasional limp home mode were all there when they hooked up the reader.

I was referring to faults that do not relate to any codes that are shown.

The fault is quite common on cars 1998-2000 often it is a poor connection on the ECU in the footwell

 

[belugablack]

Ken at Transtec Automatic Gearbox Consultants might be able to shed some light on matters. He has repaired two Mercedes' autoboxes for me, and eats, lives and breathes autoboxes with 40 years experience... one had a valve body fault and £250 and 3 days later the car drove absolutely as new. He is one of those rare old school chaps who will not charge you an arm and a leg and will always be straight with you.

He's based at Knowle, Solihull which is 5 minutes off Jn 5 of the M42, so probably just over an hour's blast up the M40 from Bicester. Transtec tel. number is: 01564 779407